Fabry disease is an X-linked inherited disorder that is caused by mutations in the α-galactosidase A (GLA) gene, which encodes an enzyme that is involved in recycling fats within the lysosomal compartments of cells. Fabry disease is also referred to as α-galactosidase A deficiency, Anderson-Fabry disease, angiokeratoma corporis diffusum, angiokeratoma diffuse, ceramide trihexosidase deficiency, Fabry's disease, GLA deficiency, and hereditary dystopic lipidosis. It has an estimated incidence of 1 in 40,000 to 400,000 males. Deegan et al., 2006 J Med. Genet. 43(4):347-352.
GLA, which is also referred to as GALA, is a homodimeric glycoprotein that hydrolyzes the terminal α-galactosyl moieties from glycolipids and glycoproteins. See, e.g., GenBank Accession Numbers NM_000169 for the GLA mRNA sequence and NP_000160 for the GLA amino acid sequence. The GLA precursor protein is 429 amino acids in length and contains a signal peptide of 31 amino acids that is cleaved during protein processing. Mutations in GLA lead to an accumulation of globotriaosylceramide (Gb3), globotriaosylsphingosine (lyso-Gb3), galabiosylceramide (Ga2), and neutral glycosphingolipids in lysosomes of several tissues, including the endothelium of the vascular tree. Gervas-Arruga et al., 2015 BMC Genet 16:109. While normal individuals have very low levels of Gb3, patients with Fabry disease progressively accumulate Gb3 in both plasma and a range of tissues.
The classic form of Fabry disease usually manifests in childhood or adolescence with periodic crises of severe pain in the extremities (acroparesthesias), the appearance of vascular cutaneous lesions (angiokeratomas), sweating abnormalities (anhydrosis, hypohydosis, and rarely hyperhidrosis), characteristic corneal and lenticular opacities, and proteinuria. End-stage renal disease usually occurs in the third to fifth decade, and even those individuals successfully treated for renal disease usually suffer from cardiac or cerebrovascular disease. Mehta et al. GeneReviews: Fabry Disease, University of Washington, Seattle (2013).
Currently, treatment for Fabry disease typically consists of diphenylhydantoin, carbamazepine, or gabapentin to reduce pain; ACE inhibitors or angiotensin receptor blockers to reduce proteinuria; and chronic hemodialysis and/or renal transplantation to treat renal disease. Enzyme replacement therapy is also often recommended, but its effectiveness is unproven. Mehta et al. GeneReviews: Fabry Disease, University of Washington, Seattle (2013). Improved therapeutics and therapies are thus needed to treat Fabry disease.